/*
 * Copyright (C) 2009 The Guava Authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
 * in compliance with the License. You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software distributed under the License
 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
 * or implied. See the License for the specific language governing permissions and limitations under
 * the License.
 */

package com.google.common.collect;

import com.google.common.annotations.GwtCompatible;
import java.io.Serializable;
import java.util.Arrays;

/**
 * A class that implements {@code Comparable} without generics, such as those found in libraries
 * that support Java 1.4 and before. Our library needs to do the bare minimum to accommodate such
 * types, though their use may still require an explicit type parameter and/or warning suppression.
 *
 * @author Kevin Bourrillion
 */
@GwtCompatible
class LegacyComparable implements Comparable, Serializable {
    static final LegacyComparable X = new LegacyComparable("x");
    static final LegacyComparable Y = new LegacyComparable("y");
    static final LegacyComparable Z = new LegacyComparable("z");

    static final Iterable<LegacyComparable> VALUES_FORWARD = Arrays.asList(X, Y, Z);
    static final Iterable<LegacyComparable> VALUES_BACKWARD = Arrays.asList(Z, Y, X);

    private final String value;

    LegacyComparable(String value) {
        this.value = value;
    }

    @Override
    public int compareTo(Object object) {
        // This method is spec'd to throw CCE if object is of the wrong type
        LegacyComparable that = (LegacyComparable) object;
        return this.value.compareTo(that.value);
    }

    @Override
    public boolean equals(Object object) {
        if (object instanceof LegacyComparable) {
            LegacyComparable that = (LegacyComparable) object;
            return this.value.equals(that.value);
        }
        return false;
    }

    @Override
    public int hashCode() {
        return value.hashCode();
    }

    private static final long serialVersionUID = 0;
}
